Create a recurring schedule

POST /v1/schedules

Sends one message to one number on a repeating wall-clock time in an IANA time zone, correct across daylight saving. Each occurrence goes through the same checks as POST /messages at the moment it fires (opt-out, sender registration, quota, spend limit, content screening) and is a normal message with schedule_id. A local time that does not exist (spring forward) runs after the gap that day; one that occurs twice (fall back) runs once, the first time. An occurrence reached more than 1 hour late is skipped (skipped_missed), never sent late. Limits: 25 active and 100 total schedules per account, at most one message per local day per schedule. Supports the Idempotency-Key header. Scope: messages:send.

Send your API key as a bearer token: Authorization: Bearer ssms_sk_.... Test keys run this endpoint against the sandbox; see Authentication for key modes and scopes.

Headers

Name	Type	Required	Description
`Idempotency-Key`	string	No	Makes retries safe for 24 hours: the same key and body replays the original successful response (with Idempotent-Replayed: true); a different body returns 409. Failed requests release the key. At most 255 characters.

Request body

JSON (Content-Type: application/json).

A ScheduleInput object.

Field	Type	Required	Description
`to`	string	Yes	Example: `+14155550132`.
`from`	string	No	One of your numbers. Optional when the account has exactly one number for the key's mode.
`body`	string	Yes	At most 1600 characters.
`repeat`	ScheduleRepeat	Yes
`start_date`	string (date)	No	First local date it may run. Defaults to today. Nullable.
`end_date`	string (date)	No	Last local date it may run (inclusive). Nullable.
`max_occurrences`	integer	No	The schedule completes after this many messages have been sent. Minimum 1. Nullable.
`category`	`marketing`, `transactional`, `otp`	No	Optional. What this message is, for quiet hours. Only marketing messages are held or refused outside 8:00am-9:00pm in the recipient's local time. Omitted: a message from a number registered for the Marketing use case is marketing, everything else is transactional. Nullable.
`quiet_hours`	`block`, `defer`	No	Optional. What to do with a marketing message in the recipient's quiet hours: `block` refuses it (403 quiet_hours), `defer` holds it until their next 8:00am. Omitted: an occurrence in quiet hours is held until the recipient's 8:00am and recorded as `deferred`. Nullable.

Responses

Status	Meaning	Body
201	Created	`Schedule`
400	Invalid request, or a limit reached	`Error`
401	Missing, malformed, or revoked API key	`Error`
402	Billable live calls only: the prepaid credit balance cannot cover the call (insufficient_credits); nothing was done or charged	`Error`
409	Idempotency conflict	`Error`
429	Rate limit or quota exceeded	`Error`

201: `Schedule` fields

Field	Type	Description
`id`	string	Example: `sch_a1B2c3D4e5F6g7H8`.
`object`	`schedule`
`to`	string
`from`	string
`body`	string
`repeat`	ScheduleRepeat
`start_date`	string (date)	Nullable.
`end_date`	string (date)	Nullable.
`max_occurrences`	integer	Nullable.
`category`	`marketing`, `transactional`, `otp`, `null`	Nullable.
`quiet_hours`	`block`, `defer`, `null`	Nullable.
`active`	boolean
`status`	`active`, `paused`, `completed`
`paused_reason`	`manual`, `recipient_opted_out`, `repeated_failures`, `sender_unavailable`, `null`	Nullable.
`next_run_at`	string (date-time)	The next occurrence (UTC). Null unless active. Nullable.
`last_run_at`	string (date-time)	Nullable.
`last_status`	`sent`, `skipped_opted_out`, `skipped_missed`, `deferred`, `failed`, `null`	Nullable.
`last_error`	string	Why the last occurrence was skipped or failed. Nullable.
`last_message_id`	string	Nullable.
`counts`	object
`counts.sent`	integer
`counts.skipped`	integer
`counts.failed`	integer
`test`	boolean	Made with a test key: only ever sends in the sandbox.
`created_at`	string (date-time)
`updated_at`	string (date-time)
`recent_occurrences`	array of object	Only on GET /schedules/{id}: the last 10 occurrences, newest first.
`recent_occurrences[].date`	string (date)	The local calendar date of the occurrence.
`recent_occurrences[].due_at`	string (date-time)	Nullable.
`recent_occurrences[].status`	`sent`, `skipped_opted_out`, `skipped_missed`, `deferred`, `failed`
`recent_occurrences[].message_id`	string	Nullable.
`recent_occurrences[].error`	string	Nullable.

Errors

Status	When
400	Invalid request, or a limit reached
401	Missing, malformed, or revoked API key
402	Billable live calls only: the prepaid credit balance cannot cover the call (insufficient_credits); nothing was done or charged
409	Idempotency conflict
429	Rate limit or quota exceeded

Every error has the same JSON shape, and request_id matches the X-Request-Id response header. Errors lists every code and what to do about it.

json

{
  "error": {
    "code": "invalid_request",
    "message": "What went wrong, in plain words.",
    "param": "the_field",
    "request_id": "req_a1B2c3D4e5F6g7H8"
  }
}

Idempotency

Send an Idempotency-Key header to make retries safe. For 24 hours the same key with the same body replays the original successful response (with Idempotent-Replayed: true); the same key with a different body returns 409. A failed request releases its key.

Examples

curl

bash

curl -X POST "https://api.joinsimplesms.com/v1/schedules" \
  -H "Authorization: Bearer $SIMPLESMS_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: 6f1c2f0e-order-1042" \
  -d '{
  "to": "+14155550132",
  "body": "Hello from SimpleSMS",
  "repeat": {
    "frequency": "daily",
    "time": "08:00",
    "timezone": "America/New_York"
  }
}'

Node.js

The Node.js SDK does not wrap this endpoint yet; call it with fetch.

javascript

const res = await fetch('https://api.joinsimplesms.com/v1/schedules', {
  method: 'POST',
  headers: {
    Authorization: `Bearer ${process.env.SIMPLESMS_API_KEY}`,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "to": "+14155550132",
    "body": "Hello from SimpleSMS",
    "repeat": {
      "frequency": "daily",
      "time": "08:00",
      "timezone": "America/New_York"
    }
  }),
});

if (!res.ok) throw new Error((await res.json()).error.message);
const data = await res.json();

Python

The Python SDK does not wrap this endpoint yet; call it over HTTP.

python

import json, os, urllib.request

req = urllib.request.Request(
    "https://api.joinsimplesms.com/v1/schedules",
    method="POST",
    headers={
        "Authorization": f"Bearer {os.environ['SIMPLESMS_API_KEY']}",
        "Content-Type": "application/json",
    },
    data=json.dumps({
        "to": "+14155550132",
        "body": "Hello from SimpleSMS",
        "repeat": {
            "frequency": "daily",
            "time": "08:00",
            "timezone": "America/New_York"
        }
    }).encode(),
)
with urllib.request.urlopen(req) as res:
    data = json.load(res)